cleanup: remove dead code and duplicate docs

- Remove session-ses_2f27.md (161KB raw session log)
- Remove 49 ROOT_* duplicate files across REFERENCE/
- Remove 14 duplicate files between REFERENCE/ root and history/
- Remove asr_legacy.rs (dead code, replaced by asr.rs)
- Remove src/core/worker/ (duplicate JobWorker)
- Remove src/core/layers/ (empty directory)
- Remove 4 .bak files in src/
- Remove 7 dead private methods in worker/processor.rs
- Remove backup directory from git tracking

scripts/asrx_self/speaker_encoder.py

@@ -33,8 +33,8 @@ def load_speaker_encoder(model_name="speechbrain/spkrec-ecapa-voxceleb"):
     )
 
     # 獲取模型資訊
-    print(f"[SpeakerEncoder] Model loaded successfully")
-    print(f"[SpeakerEncoder] Embedding dimension: 192")
+    print("[SpeakerEncoder] Model loaded successfully")
+    print("[SpeakerEncoder] Embedding dimension: 192")
 
     return classifier
 
@@ -187,5 +187,5 @@ if __name__ == "__main__":
     print(f"[Test] Embedding std: {embedding.std():.4f}")
 
     # 顯示部分嵌入值
-    print(f"\n[Test] First 10 embedding values:")
+    print("\n[Test] First 10 embedding values:")
     print(f"  {embedding[:10]}")